Food Habits of the Ural Owl (Strix uralensis) During the Breeding Season in Central Japan

Abstract

Abstract We studied the diet of Ural Owls (Strix uralensis) living in the forests of Mt. Yatsugatake, central Japan, in the context of historic logging activities that have greatly extended the amount of open pasture and consequently modified small mammal availability in the region. We used owl pellets from artificial nest boxes to quantitatively analyze diet composition during the breeding season. We identified 1026 small mammals from 17 owl nests. Mandibles were identified and categorized as wood mice (Apodemus spp.), voles (Microtus sp.), and shrew-moles (Urotrichus talpoides). The small-mammal component of the diet was dominated by wood mice (71%), followed by voles (24%) and shrew-moles (5%). This contrasts sharply with the vole-dominated diets associated with most European Ural Owl populations. We also detected significantly fewer voles among mammalian remains for nests at greater distances from open-pasture habitat. We confirmed previous results from studies of Ural Owls in Japan that suggest elast...